Page 4 of 21 · 503 questions tagged hplc.
For reference: fibrillation · 30 °C. I understand the observation; what I do not understand is the mechanism behind it. I have read the two review articles that come…
What I have: hydrolysis · 40 °C. I can predict the outcome but I cannot explain it, which means I will get the next case wrong. I would like to know how confident the…
I have the report as a PDF with the chromatogram on page two, so I can quote specifics. This is presented as though it settles something, and I am not convinced it…
This is my second independent submission on material from the same supplier. I can find plenty of assertions about this and almost no reasoning, which is usually a…
Concretely: 99.4% · liraglutide. Please show the division. I want to check my own against yours. I would like the general form as well as the specific number, so I…
Setup, so nobody has to ask: 96.8% · mazdutide. I have worked this out and I would like someone to find the error, because I suspect there is one. My working so far,…
Concretely: 96.8% · a C4 column · dulaglutide. I would like to know the limits of what can be inferred from this. What I am trying to avoid is over-reading a single…
Concretely: oxidation · 37 °C. This is one of those things that everyone repeats and nobody derives. This matters practically, not just academically, because it…
Stated plainly: Janoshik · 97.9%. I noticed this today and I have not touched anything since, in case the state is diagnostic. I have not discarded anything yet, so a…
The particulars: liraglutide · a wide-pore C18 column · semaglutide. The comparison I want does not seem to exist anywhere in a form I can evaluate. I have read the…
Numbers first: 98.4% · retatrutide. This should be a straightforward calculation and I keep getting two different answers. The numbers are arbitrary; the method is…
Concretely: aspartimide formation · 30 °C. I want to know whether this is a real physical effect or an artefact of how it is measured. What prompted the question is…
The specifics, since they change the answer: 98.4% · semaglutide. I would like the arithmetic checked rather than the conclusion asserted. I have deliberately not…
The lot number on the vial matches the certificate, which at least rules out the easy problem. I would like to know the limits of what can be inferred from this. What…
The case in front of me: PeptideMeter · 96.4%. I have two candidate explanations and no way to distinguish them. The same procedure has worked without incident…
Stated plainly: 96.4% · cagrilintide. I have worked this out and I would like someone to find the error, because I suspect there is one. My working so far, for the…
Stated plainly: 98.2% · a GLP-1 receptor agonist. I have worked this out and I would like someone to find the error, because I suspect there is one. My working so…
Conditions: PeptideMeter · 96.8%. I have two candidate explanations and no way to distinguish them. The same procedure has worked without incident several times…
Concretely: PeptideMeter · 97.9%. I think I have a problem. I am not yet sure whether it is a real problem or a measurement artefact. I want to know whether this is…
Concretely: ecnoglutide · a C4 column · tirzepatide. These are treated as interchangeable and I do not think they are. If both are acceptable I would like to know…
Conditions: ecnoglutide · a C4 column · retatrutide. These are treated as interchangeable and I do not think they are. If both are acceptable I would like to know…
Conditions: 99.4% · oral semaglutide. Please show the division. I want to check my own against yours. I would like the general form as well as the specific number, so…
Details up front: 95.2% · dulaglutide. I can do the algebra. I am not confident about the conversion factors. If there is a standard way to lay this out, I would…
For reference: liraglutide · a wide-pore C18 column · tirzepatide. I am trying to choose between two options that are usually discussed as though only one exists. I…